In recent years, the communication technologies adopted by communication electronic devices have developed from the first generation (1G) mobile communication technology to the fourth generation (4G) mobile communication technology for improving the quality of mobile communication, increasing the data transmission quantity of mobile communication, and providing more communication functions, and hence providing more convenience for users. In continuously improving and developing mobile communication technologies, short message service is still indispensable because it provides the users of communication electronic devices with an alternative communication method when they cannot contact the others real-timely through phone calls. In addition, short message service keeps improving as well, enriching the content of short messages. For example, based on short message service, multimedia message service (MMS) improves and provides another kind of short message service so that the users of communication electronic devices can transmit not only text but also multimedia files, such as photos, voice, or video, to remote users.
Accordingly, all current communication electronic devices have short message functions for enabling users to transmit communication content to remote users through short message service under the circumstance of inconvenience in using phone calls. No matter whether short messages having commercial confidentiality or personal privacy, people usually need to transmit such short messages in situations when using phone calls is not convenient. For example, two users of communication electronic devices are situated in the environment where noise is not allowed. Alternatively, users in a noisy environment, in which the listener cannot recognize the speech content clearly, and their conversation can only proceed using the text of short messages. In addition, the content of the conversation between two users, such as technical content or private account and password, can even be inappropriate to be disclosed in the public. For avoiding divulgence through spoken language, the conversation can only be performed using the text of short messages.
There are many communication technologies in our lives include encryption mechanism for ensuring the security of data transmission and prevent data from misappropriation. The most common encryption method is to set a password during the usage activation process of communication electronic devices. In the process, the user first enters a preset page, in which he has to input the password before using the communication electronic device. For example, in commercial mobile phones, a serial code corresponding to a subscriber identity module card (SIM card) is set as the activation code at start. The user has to input the serial code before he can activate the mobile phone. If the user inputs the incorrect serial code, the mobile phone will not be activated. Beside, a general communication electronic device can further let the user set a self-defined password as the activation code of the communication electronic device.
The encryption method described above can only protect communication electronic devices against activation by others but not protecting the short messages. If a user lends his communication electronic device to another after activation for using its functions, such as making phone calls, sending short messages, using the movie playback function of multimedia functions, browsing or accessing emails via mobile network by using communication electronic devices, and playing the games downloaded in communication electronic devices. At this time, if the communication electronic devices receive a short message, the short message may be opened and read by the other person owing to lack of protection measures during the reading process of short message in the communication electronic device. Consequently, private short messages, particularly those concerning account and password or other important information, might be read.
Although an encryption method has been developed presently for protecting short messages, a hardware circuit is required in the communication electronic device. In addition, when the communication electronic device reads short messages, it has to restore the short-message content, and hence increase its computational complexity, which burdens the computational circuitry and reduces the operational performance of the communication electronic device.
Accordingly, the present invention provides a method for encrypting a short message of mobile communication, which improves the problems of message being stolen owing to inability in encrypting the short message and avoids increase in computational complexity of a communication electronic device.